Cavity Drain System
The cavity drain system is an internal lining system which provides a cavity through which water will pass. The system consists of a profiled plastic wall membrane which drains to a plastic drainage channel (sited at the wall floor junction) and a profiled plastic floor membrane. Further to this sumps and pumps will also be required if natural drainage is not available.
With Cavity drain membrane all membrane joints and fixings are sealed, using specialised sealing products to prevent any ingress of water or moisture. The system can also be used as protection against contaminants such as salts, carbon deposits, fertilizers, oil etc. Because it is not possible to determine the amount of potential water pressure surrounding the structure, BS8102 tells the designer to expect a head of water to against the structure for a structure
BS8102 requires that all waterproofing is maintainable and repairable The advantage of this Cavity Drain Membrane system are that they are easily repaired, easily maintained, quickly They do not impose any load onto the structure (particularly important when dealing with older structures).
The cavity drain system would in the event of flooding rely on the effectiveness of the Maclennan-LSE pump system. We would install the system to pump the water to your drainage system. The system would be controlled by a separate control panel and the pumps would be fitted with battery back up so as they will continue working in the event of a power failure.
You should have your drainage inspected and tested to ensure it can cope the water being pumped into it.
In the event of a power failure the converter automatically switches to battery power with no loss of backup pump performance. On resumption of normal power supply the converter switches back to mains supply and trickle-charges the battery. It all adds up to complete peace of mind. The use of dual pumps allows one pump to drive the drainage system with the second on standby ready to cut in if there is a pump failure. Normal pumping operation is even assured in the event of a mains power failure providing up to 24 hours of power generally sufficient to maintain operation through most power cuts experienced in the UK. The Titan chamber also includes a Newton 9V High-water Alarm which is activated if the main pump fails or total power failure prevents the pumps from working.
We would recommend the Maclennan-LSE Membrane system in preference to cement based, Bitumen, epoxy systems or Waterproof concrete the benefits being:
- The complete system would be guaranteed for a full 20 years by Maclennan-LSE If the system is inspected and serviced annually the guarantee can be extended every 10 years for a further 10 year period.
- The system is installed after the basement construction so is unaffected by weather conditions unlike all other systems
- The system would be guaranteed by the GPI insurance guarantee so as the work would be guaranteed in the event that Maclennan-LSE should cease trading for any reason.
- The system would be very flexible and would accommodate any movement in the building.
- The system is very fast track to install and there is no drying period.
- The system can be plastered to a finish of your choosing and decorated with any products you wish.
- By installing an internal perimeter drain, sump and pump the system can be installed to deal with a certain amount of free flood water.
- The Maclennan-LSE Drain system will conform with BS 8102 .
BS8102 Does say that if the risk of water penetration is high, if for example there is a high water table and masonry construction then two forms of waterproofing should be considered. In this situation we would recommend external waterproofing as well as a cavity membrane system inside. The external system would protect the structure and prevent water penetration, however it is the internal cavity membrane that carries the guarantees and is covered by Maclennan-LSE design liability.
Unlike most installers of waterproofing systems Maclennan-LSE pay for full products insurance and professional indemnity, so that all LSE advice specification and installation is covered for all eventualities. Thus giving total peace of mind to our clients.
Finishes
A wide range of finishes can be adopted to walls, floors and soffits, which also provides protection to the membrane system. Typical wall finishes include:
- Block work wall built in front of the system
- Independent timber framing and plasterboard
- Independent metal framing systems
- Conventional plasters and renders
- Tiling and cladding
Floors
- Sand and cement screeds
- Fast drying screeds with lightweight reinforcement
- Wood-based sheets (tongue and groove flooring grade)
- Timber boarding on floor beams
- Under floor heating systems
All the above finishes can be installed with insulation, where appropriate or specified.
Environment
Any building work in a basement or below ground area will produce water, which will condensate on cold surfaces for a short period of time during and after the work. The basement heating, ventilation and insulation should be designed to remove excess moisture vapour so the basement has a comfortable environment free from condensation. Environmental control is not a part of the water proofing design or installation and should be designed by a qualified mechanical electrical engineer.
